Glenn Fair enough, but these bandwidths are still much greater than the 20kHz cited. Group delay is still a problem, maybe not as bad as a 10GHz digital system, but still worth consideration, especially if running higher order modulation schemes. As an illustration of larger RF bandwidths, electronics warfare systems can easily have 10-20GHz of received bandwidth per antenna. The RF front end then may channelise this, to more manageable bandwidths e.g 1-2GHz, but somewhere on the RF board there will still be the full bandwidth. Andrew ________________________________ From: glenn_wood@xxxxxxxxxxx [mailto:glenn_wood@xxxxxxxxxxx] Sent: Wed 24/08/2005 18:33 To: Andrew Burnside; si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Re: RF board Vs High speed board ... RF amplifiers Does anyone know of any off the shelf parts that can *linearly* amplify Ultra Wideband Signals and with a F3dB as high as 10GHz? Actually, in this case, the carrier can be considered to be 2.5GHz and the bandwidth extends down to 500MHz (or 0.2 of carrier). Thanks -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx]On Behalf Of Andrew Burnside Sent: Wednesday, August 24, 2005 11:05 AM To: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Re: RF board Vs High speed board Hi Lynne/John RF signals are not necessarily narrowband. For example, Ultra Wideband Signals (becoming more common these days) have a bandwidth of at least 0.25 of the carrier frequency. The other case that wideband RF is often seen on boards these days is in Direct Digital Downconversion architectures. You might see in excess of 1GHz going into ADCs, and that's only the IF! In this case the wideband IF often contains several signals. Usually some steps have been taken by the implementer of an RF system to limit the bandwidth, similar to pre-emphasis and de-emphasis in a high speed digital system. So usually the RF board will have slightly more rounded signals, but these may have higher rms power than the high speed digital system, especially in a PA subsystem. Regards Andrew ________________________________ From: si-list-bounce@xxxxxxxxxxxxx on behalf of Lynne D. Green Sent: Wed 24/08/2005 17:27 To: johnnfaq@xxxxxxxxx; si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Re: RF board Vs High speed board Hello, John, RF signals are "narrow band", i.e. modulation is superimposed on a carrier frequency. The modulation bandwidth is significantly smaller than the carrier frequency (your car radio is a good example - carrier is around 100kHz, bandwidth is around 20kHz.) RF requires filtering to remove the carrier and recover the signal. High-speed signals are "wide band", i.e. they have significant frequency content from DC to hundreds of times the modulation rate. For an ideal interconnect, filtering is not required to recover the original signal. (And, although rates are usually given in MHz, they really mean Mbaud.) Best regards, Lynne "IBIS training when you need it, where you need it." Dr. Lynne Green Green Streak Programs http://www.greenstreakprograms.com 425-788-0412 lgreen22@xxxxxxxxxxxxxx -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of johnn william Sent: Wednesday, August 24, 2005 4:19 AM To: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] RF board Vs High speed board Hi All, Please anyone in group clarify the difference in handling the RF board compared to normal High speed boards. Thanks in advance. John ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu